The invention apparatus comprises an electrical circuit for controlling a sewing machine and more particularly comprises a microprocessor for accessing stored pattern data in main memory and using said patterns to control the sewing machine fabric and needle mechanisms.
Sewing machines comprising mechanical cam arrangements for sewing patterns are available but are not reliable due to dust and friction problems normally associated with complicated cam linkages.
An electrical controller is described in U.S. Pat. Nos. 3,872,808 and 3,885,956. However, these machines are limited to the sewing of single patterns of unvarying size and shape. A more flexible machine offering a greater range of pattern forms and an automatic selection of patterns is needed.